Coffee substitutes have been prepared from a wide variety of starch bearing materials, including wheat, corn, rye, barley, beans, peas, nuts, etc. Usually, the material to be extracted is washed, dried, roasted and extracted. To counteract the bitter taste usually associated with such beverages, the prior art has, prior to roasting, mixed the extractable matter with sugar or with bran coated with carmelized saccharine.
While consumer acceptance of these substitute beverages, such as Postum.TM. , has been acceptable, the great majority of consumers are unable to accept these products as a substitute for coffee, due to their somewhat inferior taste, aroma and flavor.
In U.S. Pat. No. 4,137,324 to Shirbroun, green soy beans are defatted, preferably by crushing, prior to grinding and roasting. In one embodiment, the green soybeans are presoaked prior to crushing and defatting. Thereafter, the crushed, defatted soybeans are dried at 250.degree. F. to 350.degree. F. to a moisture content of from 11 to 13 wt. %. The dried soybeans are then ground and roasted. Shirbroun prefers slow roasting, preferably at 350.degree. F. to 375.degree. F., for up to 45 minutes, until the product has the appearance of ground coffee.
While consumers described the brewed Shirbroun product as having the appearance and taste of coffee, they also noted some soy aroma. To many coffee drinkers, aroma is essential to the enjoyment of coffee. Accordingly, the Shirbroun product is not entirely satisfactory to all coffee drinkers.
The aroma of coffee arises from the complex interaction of over 500 known volatile compounds and many unknown volatile compounds. The defatting of the soybean removes several lipids whose decomposition during roasting may influence the aroma of the roasted beans. Also, roasting alone does not always destroy the compounds responsible for soy aromas. Therefore, the Shirbroun products lack of the characteristic coffee aroma is not entirely surprising in light of the methods employed to process the soybeans.
Moreover, Shirbroun never suggests or attempts to make a satisfactory beverage which can substitute for an instant coffee. It is well known that instant hot beverages lack some of the flavor and aroma of the originally brewed product. Therefore, any lack of coffee flavor or aroma in a brewed product will be exaggerated in an instant product prepared from that brew.